The chief executive of West Middlesex Hospital, Tara Donnelly, has stepped down and a government task force called in after eight patients were left waiting for beds for more than 12 hours.

The patients were marooned in A&E because no space in the main hospital could be found as the West Mid buckled under the weight of demand on January 19.

Bosses at the hospital, in Twickenham Road, Isleworth, also failed to report the mounting crisis to the relevant authorities and therefore received no help.

Chief executive Tara Donnelly has acknowledged the 'seriousness' of the situation and resigned, according to a statement released by the hospital yesterday evening.

In the statement, Sue Ellen, chairman of the hospital trust, added: "Eight patients waited longer for admission than we consider acceptable and on this occasion we did not deliver the expected standard of care.

"The board has launched an internal investigation to review how the hospital can ensure it avoids unnecessary waiting times in the future.

"In addition we have been advised that a task force will be conducting a further independent review of our emergency admissions procedures."

The hospital blamed 'winter pressures' for the 12-hour delays - which is above the target imposed by Whitehall health chiefs.

"The trust also failed to follow the correct protocol in escalating within the sector and reporting the Strategic Health Authority (SHA)," added Ms Ellen. "This denied other trusts in the sector and the SHA the opportunity to provide assistance."

Details of the interim chief executive will be announced in the coming weeks but Simon Marshall, director of finance and performance, will assume the role in the meantime.

The announcement follows a week of rumours surrounding the stability of Tara Donnelly's position and individual cases of patient failure.

During her two years at the trust she spearheaded a number of projects, including the opening of the Natural Birth Centre last year.

"On behalf of the trust board I would like to thank Tara for her significant contribution and to wish her well for the future," said Ms Ellen.

The West Mid would not confirm the circumstances surrounding the eight individual cases, including their exact waiting time and whether they were left on trolleys, citing the ongoing investigation.